We realy should be starting to descriminate between different types of wave piercers (I dislike that description as well by the way.) We have several shapes right now after the Flyer introduced the concept. And the Flyer hull is different from teh FX-one which is different from the Bimare shapes which in turn can not be compared to that of the Blade. Some designers try to design "wave piercer hulls" by reducing bouyance fore and aft in the hull. Others by moveing this bouyancy away from the extremeties towards the centre under the main beam. And another implements this by only redistributing the bouyancy in the vertical direction while keeping the destribution in the horizontal sense unchanged. The different paths lead to the boats behaving differently under certain conditions. There is even a difference between the Hobie Fox and the Hobie FX-one in my personal experience. Therefor I don't think it can be stated that :"spi + planing wave piercing hulls don't mix!". It dependent on the design path followed.

The same must be set about displacement boats however. An Inter-18 is different from a Nacra F18 in this respect as well despite the fact that neither are regarded as "Wave piercers".

My questions are:

1) Has anyone else seen this? Cat and windspeed?
2) Has anyone seen this on cats with "plowing" hulls? Cat and windspeed?

No further comment on these points, I'm too involved.

3) Why does this happen to "planing" and not to "plowing" hulls?

It can to happen to both depending on the individual design of the boat.

4) If others have observed this, how is it influenced by boat weight and hull length (and why) - ie, would the same phenomenon be seen on A-cats, FXOne, and planing F16's such as Stealth/Blade (but not seen on I17 and T4.9)?

In your list of examples you have actually listed boats under "don't" that do and visa versa


Wouter